I refill empty water bottles to freeze for use in my big freezer all year. When I need to use an ice chest, I just remove enough to keep items cold. When a hurricane approaches, I put as many new unopened bottles of water as possible to freeze several days in advance, then as the days go without power I have “ice cold” bottles of water to drink. I’ve been through a lot of hurricanes in Southeast Louisiana over the years. We were just without power 9 days after “Gustav” and with solid ice and a generator that we ran half time, we survived with no loss in freezer and refrigerator. The best way to survive power outages is to have the freezer completely full of ice. Use any type of sealable bottle or container to keep you from having a “water mess” to deal with in case of thawing.